• 제목/요약/키워드: Feeding activity

검색결과 936건 처리시간 0.025초

노래미, Agrammus agrammus의 일주섭식활동에 관한 수리적 접근 (Mathematical Approaches Related to Daily Feeding Activities of Rock Trout, Agrammus agrammus)

  • 김종관;강용주
    • 한국수산과학회지
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    • 제24권5호
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    • pp.315-326
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    • 1991
  • 본 조사는 노래미(Agrammus agrmmus)의 위만복도의 일주변화에 관한 수리적 접근을 시도한 것이다. 표본은 삼천포 신수도 연안에서 1984년 9월부터 1985년 8월사이에 낚시와 삼중자강으로 채집된 것이다. 하루 중 위만복도는 이른 아침과 늦은 오후에 각각 한차례씩 증가하였고, 늦은 오전과 정오무렵 및 야간에는 감소하였다. 즉, 노래미의 섭식활동은 해뜰무렵과 해질무렵에 강하였다. 본 종의 하루 중 일주섭식활동은 위배출만 일어나는 시간대와 섭식과 위배출이 동시에 일어나는 시간대로 구분할 수 있었다. 위배출 시간대에서 시간의 경과에 따른 위만복도는 지수 함수적으로 감소하였고, 섭식과 위배출이 동시에 일어나는 시간대에서 시간의 경과에 따른 위만복도는 단위시간당 위배출률과 섭식률, 위의 최대만복도 등에 영향을 받았다. 위배출률은 위배출 시간대에서 시간 t와 t시점에서의 위만복도 $F_t$, 간, 또는 $F_t$$t+\Delta t$시점에서의 위만복도 $F+_{\Delta t}$, 간의 회귀관계식으로분터 회귀계수를 추정하는 방법으로써 구할 수 있었다. 섭식률과 위의 최대만복도는 섭식과 위배출이 동시에 일어나는 시간대에서 $F_t$$t+\Delta t$간의 회귀관계식으로부터 추정할 수 있었다. 섭식률과 위배출률은 봄에 높았고 겨울에 낮았다. 본 종의 일주섭식활동에 관한 가설들로부터 추논된 위배출 시간대와 섭식과 위배출이 동시에 일어나는 시간대에서 시간 t와 t시점에서의 위만복도 $F_t$, 간의 관계식은 각각 아래와 같다. $$F_t=F_{to}e^{-r(t-to)}$$, $$F_t=F\infty-(F\infty-F_{to})e^{-(p+r)(t-{to})}$$

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Identification of a neural pathway governing satiety in Drosophila

  • Min, Soohong;Chung, Jongkyeong
    • BMB Reports
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    • 제49권3호
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    • pp.137-138
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    • 2016
  • Satiety cues a feeding animal to cease further ingestion of food, thus protecting it from excessive energy gain. Impaired control of satiety is often associated with feeding-related disorders such as obesity. In our recent study, we reported the identification of a neural pathway that expresses the myoinhibitory peptide (MIP), critical for satiety responses in Drosophila. Targeted silencing of MIP neuron activity strikingly increased the body weight (BW) through elevated food intake. Similarly, genetic disruption of the gene encoding MIP also elevated feeding and BW. Suppressing the MIP pathway behaviorally transformed the satiated flies to feed similar to the starved ones, with augmented sensitivity to food. Conversely, temporal activation of MIP neuron markedly reduced the food intake and BW, and blunted the sensitivity of the starved flies to food as if they have been satiated. Shortly after termination of MIP neuron activation, the reduced BW reverted to the normal level along with a strong feeding rebound. Together our results reveal the switch-like role of the MIP pathway in feeding regulation by controlling satiety.

Direct Examination of the Dietary Preference of the Copepod Calanus helgolandicus Using the Colorimetric Approach

  • Kang, Hyung-Ku;Poulet, Serge;Ju, Se-Jong
    • Ocean Science Journal
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    • 제42권3호
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    • pp.193-197
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    • 2007
  • The food selectivity of tethered females of the copepod Calanus helgolandicus was examined by using the colorimetric approach. First, feeding behavior of the copepod did not show any differences between the red-color stained with neutral red and non-stained diets using the diatom Coscinodiscus curvatulus. Then, the copepods were fed a mixtures of two diets, the diatom C. curvatulus, stained with neutral red, and the dinoflagellate Gymnodinium sanguineum for $14\sim60$ minutes of feeding duration. The foregut colors of females were examined using a stereo-microscope and a video monitor. The foreguts of animals fed with a high density of diatoms in mixed diets showed a dark red color, whereas those fed with a high density of dinoflagellate in mixed diets were a dark yellow. The results suggest that this species of copepod may not selectively feed either one of the diets used for this study. Their feeding activity may be more likely related to the density of available prey in their environment. Therefore, this quick and easy colorimetric approach could provide very useful information, like the pre-screening procedure before designing and conducting the time-consuming and complex feeding experiments to understand the feeding ecology of copepods.

벌꿀이 흰쥐의 효소활성에 미치는 영향 (Effect of Honey on the Change of Enzyme Activity in Rats)

  • 정동현;백승화;박성수
    • 한국식품영양학회지
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    • 제10권1호
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    • pp.65-73
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    • 1997
  • 본 실험은 벌꿀이 흰쥐(Sprague Dawley, ♂)의 효소활성에 미치는 영향을 구명하고저 설탕, 아카시아, 붉나무 그리고 잡화벌꿀을 각각 10%와 20%의 수용액으로 만들어 7주간 섭취 한 후 벌꿀의 효과를 비교한 바 다음과 같은 결론을 얻었다. LDH활성은 대조군에 비하여 아카시아꿀, 붉나무꿀, 잡화꿀용액 섭취군에서 증가하였다. $\alpha$-HBDH활성은 설탕용액, 아카시아꿀, 붉나무꿀, 잡화꿀용액 섭취군이 대조군에 비하여 증가하였다. 벌꿀 섭취군 중 20% 아카시아꿀 용액만 GOT, GPT의 활성이 증가하였다. ICD활성은 붉나무꿀 용액에서 증가하였으나 아카시아 및 잡화꿀 용액에서 뚜렷하게 감소되었다. 벌꿀용액 섭취는 PHI, 전혈 G-6-P DH 활성을 감소시켰으나, aldolase역가를 증가시키는 경향이었다.

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수소기질 결핍 및 공급 기간비 변화에 따른 슬러지 입상화 (Sludge Granulation Depending Hydrogen Feeding on The Varying Periods of Hydrogen Feeding and Starvation)

  • 정병곤;이헌모;양병수
    • 한국환경과학회지
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    • 제5권3호
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    • pp.387-398
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    • 1996
  • Granular sludge formation and it's activity change are the most important factors in achieving successful start-up and operation of UASB reactor. Nevertheless, the detailed mechanism is still unknown. On the basic of the experiments in laboratory-scale UASB reactor, the effect of hydrogen partial pressure on sludge granulation was evaluated. Size distribution method and specific metabolic activity of the sludge with the operation time were used as a means for estimating the degree of the sludge granulation. At the constant hydrogen loading, the granulation increased as starvation periods in hydrogen supply increased, resulting in high organic removal efficiency. It was evidient that hydrogen play very important role in granulation and sludge granulation was achieved through mutual symbiosis between hydrogen utilizing bacteria and hydrogen producing bacteria under the hydrogen dificient conditions. Key words : granular sludge, UASB reactor, hydrogen partial pressure.

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1,8-cineole protected human lipoproteins from modification by oxidation and glycation and exhibited serum lipid-lowering and anti-inflammatory activity in zebrafish

  • Cho, Kyung-Hyun
    • BMB Reports
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    • 제45권10호
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    • pp.565-570
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    • 2012
  • We recently reported that a water extract of laurel or turmeric, 1,8-cineole enriched fractions, showed hypolipidemic activity in the zebrafish model. Therefore, the present study investigated the cineole's anti-oxidant and anti-inflammatory activities in lipoprotein metabolism in vitro and in vivo. Cineole had inhibitory effects on cupric ion-mediated oxidation of lipoproteins in general, while simultaneously enhancing ferric ion removal ability in high-density lipoprotein (HDL). Hypercholesterolemia was induced in zebrafish using cholesterol-feeding treatment, 4% cholesterol, for 3 weeks. After feeding with or without the addition of cineole, the results revealed that cineole possessed lipid-lowering and anti-inflammatory activities in hypercholesterolemic zebrafish. In addition, serum amyloid A and interleukin-6 levels were lowered and lipid accumulation was decreased in the liver. Conclusively, 1,8-cineole was found to have anti-oxidant activities in lipoprotein metabolism both in vitro and in vivo with simultaneous reduction of lipid accumulation in the liver of zebrafish.

해상 가두리 양식장 암모니아 모니터링 시스템에 관한 연구 (A Study on the Monitoring System for Ocean Fish Farm)

  • 오진석
    • 한국항해항만학회지
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    • 제30권8호
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    • pp.721-727
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    • 2006
  • 해상 가두리 양식장은 수중 내 암모니아성 질소 배설물을 제거 할 수 있는 것이 불가능하다. 암모니아성 질소를 효과적으로 제거하지 못하여 대량 폐사를 하거나 섭이 활동을 저하 시키는 원인이 된다. 또한 공급된 사료를 어류들의 섭이 활동 저하로 낭비 되는 것이 현실이다. 이러한 문제점을 해결하기 위하여 해상 가두리 양식장의 환경 요인 중에 암모니아를 원격에서 자동으로 측정하고 감시 할 수 있는 장치를 구성 하고자 한다.

누에 유충의 혈림프 유약호르몬 에스테라제 활성의 조절에 관한 연구 (Regulation of Haemolymph Juvenile Hormone Esterase Activity in Larvae of the Silkworm, Bombyx mori)

  • 손흥대;강필돈
    • 한국잠사곤충학회지
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    • 제34권1호
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    • pp.15-20
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    • 1992
  • 누에의 5령유충 섭식기 동안 절식, 두흉부 결찰, 재섭식 및 methoprene 등의 처리가 JHE 활성도의 조절에 미치는 영향을 실험한 바 그 결과는 다음과 같다. 1. 누에의 절식 및 결찰처리를 하면 혈림프 JHE 활성도가 감소하였다. 2. 절식누에는 재섭식에 의해 JHE 활성도가 증가하였으며, 재섭식에 의한 JHE 활성도의 증가시기는 절식기간에 따라 다르게 나타났다. 3. 절식누에에 methoprene을 투여하면 JHE 활성도는 5령 기잠과 1일에서는 변화가 없었으나 2일부터 5일에서 절식누에에 비해 1.3-1.4배 증가하였다. 4. 결찰누에에 methoprene을 처리하면 JHE 활성도는 5령 기잠에 변화가 없었고 1일부터 5일에서는 결찰누에에 비해 1.9-2.3배 증가하였다. 5. 이상의 결과에서 5령누에의 섭식기 동안 JHE 활성도의 조절에는 두부요인, JH 및 영양 등이 중요한 요인으로 작용하였다 .특히 섭식기에 있어서 JHE는 두부요인과 JH의 공동작용에 의해 조절되지만, 령의 초기에는 두부요인이 그 후에는 JH가 보다 중요한 역할을 하는 것으로 생각된다.

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Effect of Work Stress and Supplementary Feeding on Body Conformation, Ovarian Activity and Blood Parameters in Mashona Cows in a Smallholder Farming System

  • Chimonyo, M.;Kusina, N.T.;Hamudikuwauda, H.;Nyoni, O.
    • Asian-Australasian Journal of Animal Sciences
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    • 제13권8호
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    • pp.1054-1058
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    • 2000
  • The objective of this study was to determine the effect of draught stress on certain haemograms and ovarian activity and the influence of dietary supplementation on the negative effects of draught in cows. Blood parameters and ovarian activity were assessed in supplemented non-working (SNW), supplemented working (SW) and non-supplemented non-working (NSNW) cows. Body weights and body condition scores were recorded fortnightly. Blood samples were collected through jugular venipuncture in December, February and April to determine the contents of haematocrit, erythrocyte, haemoglobin and white blood cells. Ovarian palpations were carried out in October, January and April. The SW cows maintained body weights (p>0.05) during the monitoring period whereas both SNW and NSNW cows gained (p<0.05) body weights. Body condition scores were similar between SW and NSNW cows. Cows in the NSNW group had lower (p<0.05) haematocrit concentrations in April than both supplemented groups. In December, erythrocyte concentrations were similar (p>0.05) among all treatment groups. Haemoglobin concentrations were higher (p<0.05) in SW and SNW cows in February and April than in December. The SW cows had higher leucocyte contents (p<0.05) in February than the other groups of cows. All treatment groups showed similar (p>0.05) ovarian activity in January. However, the NSNW group showed a lower proportion (p<0.05) of cows that exhibited normal ovarian activity in April. The results suggest that dietary supplementation of cows increases haematocrit and haemoglobin contents. In addition, supplementary feeding during the period of draught power provision maintains ovarian activity in cows.